Method and apparatus for controlling railway switches

ABSTRACT

The invention provides a railroad switch for use in un-signaled (dark) territory. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

CROSS REFERENCE TO RELATED APPLICATIONS

The invention is related to, and claims priority from United StatesProvisional patent application Ser. No. 11/028,753, filed on Jan. 3,2005, by Beaman, et al., and entitled METHOD AND APPARATUS FORCONTROLLING RAILWAY SWITCHES.

FIELD OF INVENTION

The present invention relates generally to railroad infrastructure, andmore particularly to railroad switches in un-signaled (dark) territory.

PROBLEM STATEMENT Interpretation Considerations

This section describes the technical field in more detail, and discussesproblems encountered in the technical field. This section does notdescribe prior art as defined for purposes of anticipation orobviousness under 35 U.S.C. section 102 or 35 U.S.C. section 103. Thus,nothing stated in the Problem Statement is to be construed as prior art.

Discussion

The United States rail system is currently comprised of approximately143,000 track miles, of which, approximately only 70,000 miles arecurrently signaled. Signal systems are generally comprised of waysidesignals, power operated switches, vital track circuits, and “vital”field logic implemented in either relay based systems, or solid statedevices (note that the use of the term “vital” in this application isassociated in the industry with known performance parameters, and doesnot mean “vital” in a patentability sense, or patent-interpretationsense, unless otherwise explicitly stated in writing). The signalsystems provide for the safe control and movement of railway vehiclesthrough the operation of the signals and switches. This control ispredominantly accomplished through the use of Centralized TrafficControl (CTC) systems where a dispatcher remotely controls the signalsand switches. Signal systems, CTC systems, and their components, arewell known and understood in the current art. Such systems are notapplied universally due to the high costs of acquisition andmaintenance.

The remaining 70,000 miles of track are considered to be “dark”territory. Movement of railway vehicles in dark territory is governed byverbal authorities issued by a dispatcher thereby maintaining the safeseparation and movement of the railway vehicles. Movement of railwayvehicles to and from the mainline track is accomplished by the use ofhand-operated manual switch stands to affect the movement of the switchpoints. The use of mainline hand-operated switches is governed byfederal regulation 49CFR236.410 which requires, among other things, thathand-operated mainline switches remain locked in the normal positionwhen not in use. The use of hand-operated manual switches in darkterritory pose several distinct problems:

Security

Switches have inadvertently not been returned to normal, or haveintentionally been tampered with, thereby unexpectedly diverting arailway vehicle from the main track. In many instances this can, andhas, resulted in derailments, and, or, collisions with standingequipment.

Efficiency

One of the primary applications of hand-operated switches is to controlthe movements of railway vehicles to and from passing sidings. Passingsidings allow two or more railway vehicles to either meet (movement inopposing directions) or to pass (movement in same direction). Thesetypes of moves may require multiple movements of one or more of thevehicles in order to correctly position the switches, and manage thecrew members.

Safety

The crew member is exposed to injury by the acts of disembarking andre-embarking the vehicle and also by the physical and climaticconditions in the vicinity of the switch.

Thus, there is a need to provide an approach for dark territoryswitching that provides greater security than the traditional lockingmechanisms and operating practices without the use of vitalcommunications links to a central location, or requiring a centraldispatching system or requiring a vital processor.

BRIEF DESCRIPTION OF THE DRAWINGS AND TABLES

Various aspects of the invention, as well as an embodiment, are betterunderstood by reference to the following detailed description. To betterunderstand the invention, the detailed description should be read inconjunction with the drawings and tables, in which:

FIG. 1 is a block schematic 100 showing a system for a remotelycontrolled switch.

FIG. 2 is a block diagram of MCU.

FIG. 3 is a block schematic that shows one embodiment of the trackcircuits.

FIG. 4A is a diagram depicting a power-operated switch.

FIG. 4B is a diagram that illustrates the application and modificationsof the power-operated switch.

FIG. 5 illustrates the application of an exemplary switch circuitcontroller.

FIG. 6 is a diagram depicting PLC inputs.

FIG. 7 is a diagram depicting PLC outputs.

FIG. 8 is a switch algorithm 800, which may be practiced as software.

Table 1 shows user-controlled parameters.

Mnemonics List provides code for implementing one embodiment of theinvention.

EXEMPLARY EMBODIMENT OF A BEST MODE Interpretation Considerations

When reading this section (An Exemplary Embodiment of a Best Mode, whichdescribes an exemplary embodiment of the best mode of the invention,hereinafter “exemplary embodiment”), one should keep in mind severalpoints. First, the following exemplary embodiment is what the inventorbelieves to be the best mode for practicing the invention at the timethis patent was filed. Thus, since one of ordinary skill in the art mayrecognize from the following exemplary embodiment that substantiallyequivalent structures or substantially equivalent acts may be used toachieve the same results in exactly the same way, or to achieve the sameresults in a not dissimilar way, the following exemplary embodimentshould not be interpreted as limiting the invention to one embodiment.

Likewise, individual aspects (sometimes called species) of the inventionare provided as examples, and, accordingly, one of ordinary skill in theart may recognize from a following exemplary structure (or a followingexemplary act) that a substantially equivalent structure orsubstantially equivalent act may be used to either achieve the sameresults in substantially the same way, or to achieve the same results ina not dissimilar way.

Accordingly, the discussion of a species (or a specific item) invokesthe genus (the class of items) to which that species belongs as well asrelated species in that genus. Likewise, the recitation of a genusinvokes the species known in the art. Furthermore, it is recognized thatas technology develops, a number of additional alternatives to achievean aspect of the invention may arise. Such advances are herebyincorporated within their respective genus, and should be recognized asbeing functionally equivalent or structurally equivalent to the aspectshown or described.

Second, the only essential aspects of the invention are identified bythe claims. Thus, aspects of the invention, including elements, acts,functions, and relationships (shown or described) should not beinterpreted as being essential unless they are explicitly described andidentified as being essential. Third, a function or an act should beinterpreted as incorporating all modes of doing that function or act,unless otherwise explicitly stated (for example, one recognizes that“tacking” may be done by nailing, stapling, gluing, hot gunning,riveting, etc., and so a use of the word tacking invokes stapling,gluing, etc., and all other modes of that word and similar words, suchas “attaching”).

Fourth, unless explicitly stated otherwise, conjunctive words (such as“or”, “and”, “including”, or “comprising” for example) should beinterpreted in the inclusive, not the exclusive, sense. Fifth, the words“means” and “step” are provided to facilitate the reader's understandingof the invention and do not mean “means” or “step” as defined in §112,paragraph 6 of 35 U.S.C., unless used as “means for—functioning—” or“step for—functioning—” in the Claims section. Sixth, the invention isalso described in view of the Festo decisions, and, in that regard, theclaims and the invention incorporate equivalents known, unknown,foreseeable, and unforeseeable. Seventh, the language and each word usedin the invention should be given the ordinary interpretation of thelanguage and the word, unless indicated otherwise.

As will be understood by those of ordinary skill in the art, variousstructures and devices are depicted in block diagram form in order toavoid unnecessarily obscuring the invention. As used, herein and theaccompanying drawings, B12 refers to positive 12 volts, and N12 refersto negative 12 volts. Additionally the term “set” refers to theapplication of 12 volts (B12), while the term “reset” refers to theremoval of 12 volts.

Some methods of the invention may be practiced by placing the inventionon a computer-readable medium. Computer-readable mediums include passivedata storage, such as a random access memory (RAM) as well assemi-permanent data storage such as a compact disk read only memory(CD-ROM). In addition, the invention may be embodied in the RAM of acomputer and effectively transform a standard computer into a newspecific computing machine.

Data elements are organizations of data. One data element could be asimple electric signal placed on a data cable. One common and moresophisticated data element is called a packet. Other data elements couldinclude packets with additional headers/footers/flags. Data signalscomprise data, and are carried across transmission mediums and store andtransport various data structures, and, thus, may be used to transportthe invention. It should be noted in the following discussion that actswith like names are performed in like manners, unless otherwise stated.

Of course, the foregoing discussions and definitions are provided forclarification purposes and are not limiting. Words and phrases are to begiven their ordinary plain meaning unless indicated otherwise.

DESCRIPTION OF THE DRAWINGS System Overview

FIG. 1 is a block schematic 100 showing a system for a remotelycontrolled switch. According to one embodiment, a switch 108 ismechanically coupled to a set of switch points (points) 124. It isunderstood that switch points, rather than being points in amathematical sense, are the terminal portion of a railroad track. In thepresent example, the switch points 124 are the terminal portion of therailroad tracks 126 that move. Operation of the switch 108 moves thepoints 124 to either the normal or reverse positions. The preferredswitch being a power operated spring switch such as model LP3000manufactured by General Electric Transportation Systems™ or a similarsystem known to those of skill in the art. However, any power-operatedswitch manufactured for railway applications may be used and theinvention is not limited to any particular switch. Switch 108 contains acontroller 110 and a Dual Tone Multiple Frequency (DTMF) module 112 (aDTMF module decodes tones and executes commands based on the tonesand/or the sequence of those tones). Controller 110 governs and controlsthe operations of the switch. DTMF module 112 provides a method ofcommand input and status output (this is in addition to the serial andelectromechanical methods provided by controller 110). Any externalpower source may be used including but not limited to any AC powersource, any DC power source (along with the appropriate converters), ora remote power source such as a solar charging system 122.

A switch circuit controller (SWCC) 114 is connected to the points 124 toprovide a secondary position indication. Additionally, two “vital” trackcircuits 102 are provided: On-Switch circuit 102A (OS-A), and On-Switchcircuit 102B (OS-B) (keep in mind that “vital” herein is a term of art,and does not mean that an item is “vital to the invention”). Thecircuits 102A and 102B detect the presence of a train on a short tracksegment. Any vital track circuit or equivalent manufactured for railwayapplications may be used. Additionally, the track circuits, as used,provide a zone of protection around and including the switch points thatincludes the facing point side and trailing point sides on both thenormal and reverse sides of the switch. “Facing point” and “trailingpoint” are terms known in the art; but for the benefit of the generalreader, the facing point direction is the direction a train takes whenmoving into a switch from facing point to trailing point, and thetrailing point direction is the direction a train takes when moving intoa switch from trailing point to facing point.

The invention is not limited to a particular number of On-Switchcircuits, but includes any number and style of circuits that provide therequired zone of protection. In addition, it is also understood in theart that in the present context, the term “Sheet” and “Segment” areinterchangeable with the term “Switch.” These circuits can include, butare not limited to, AC circuits, DC circuits, and wheel detectors. Ofcourse, it is understood in the art that the specific selection, design,and application of track circuits are dependent on environmental andoperational factors.

A plurality of switch position indicators 116 are provided that, in oneembodiment, each contain a three-color single aspect display mechanismfor visually displaying the status of the switch points 124. Forexample, in one embodiment, the colors may be RED, YELLOW, and GREEN.The display colors may be provided for by any mechanism approved forrailway use and the invention includes but is not limited to LEDdisplays and filament displays. Two indicators 116 provide a visualindication of the status of the switch points 124 to railway vehicleswith the indicators 116 positioned in close proximity to switch 108. Thefirst indicator 116 provides indications to railway vehicles approachingthe facing points 124 and the second indicator provides indications torailway vehicles approaching the trailing points 124. The actualplacement of the indicators 116 is dependant on environmentalconsiderations.

A communication system is provided that is comprised of a wirelesscommunication device, such as radios 104A and 104B: where radio 104Acouples to the Main Control Unit (MCU) 118, and radio 104B is providedfor railway vehicles and railway personnel (radios 104A and 104Bpreferably have DTMF capabilities). Of course, other wirelesscommunication devices interchangeable with radios are usable as will bereadily apparent to those of skill in the art upon reading the presentdisclosure. The communication system is utilized, at least in part, toprovide remote control and indication messages. Additionally, theinvention is not limited to any particular communication means or methodand can include but is not limited to: digital communications, analogcommunications, copper, fiber optics, Local Area Networks (LAN), or WideArea Networks (WAN), for example. According, MCU 118 is provided toallow for the safe operation of the switch.

Of course, this section discusses exemplary portions of an exemplaryembodiment of the invention. It is understood that equivalent portions,sometimes having equivalent devices and means, may be substituted, andare readily apparent to those of ordinary skill in the art after readingthis disclosure.

Main Control Unit

FIG. 2 is a block diagram of MCU 118. MCU 118 contains two programmablelogic controllers (PLC) 202A and 202B. Programmable logic controllers202 may be implements as Micro3C™ model number FC2AC24A4C manufacturedby the IDEC™ Corporation. However, any programmable logic controllerwith similar operating characteristics, such as a Digital SignalProcessor (DSP), may be used, and the invention is not limited to anyparticular programmable logic controller. Additionally, programmablelogic controllers (PLCs) 202 may be programmed according to a ladderlogic or mnemonic method, for example.

MCU 118 contains four vital relays 203 and five non-vital relays 204.Vital relays 203 are model 4000004 manufactured by Safetran™. Relays 204are non-vital relays model RH4B-UL manufactured by the IDECCorporation™. Of course, these relays are exemplary and any equivalentrelay providing similar operating characteristics may be used.

Relays 204A-E are used to repeat the status of various conditions andstates of the system. Contacts for relays 204 are used as inputs tologic controllers 202 and as part of logic circuits. Relay 204A is thenormal position repeater (NWKP). Relay 204B is the reverse positionrepeater (RWKP). Relay 204C is the normal control repeater (NWZP). Relay204D is the reverse control repeater (RWZP). Relay 204E is the trackcircuit repeater (OSTP). Relay 204E represents the logical AND of trackcircuits 102 in the system.

Vital relays (relay) 203 provide(s) for various functions within the MCU118. Each relay 203 operates on a closed-circuit principal whereby therelay coils are energized when denoting a least restrictive state. Relay203A is a Vital Lock Relay (VLR) that operates as a master relay. Relay203A is set when the system is operating correctly. A failure of thesystem causes power to be removed from relay 203A thereby preventingoperation of the system. Relay 203B is the Lock Relay (LR) that operatesas a locking mechanism for the system. Power is removed from relay 203Bunder various conditions including, but not limited too, the presence ofa railway vehicle as determined by track circuits 102. Relay 203C is thetrack circuit 102A repeater (OS-AP). Relay 203C repeats the status oftrack circuit 102A and is used for input to logic controllers 202. Relay203D is the track circuit 102B repeater (OS-BP). Relay 203D repeats thestatus of track circuit 102A and is used for input to logic controllers202.

The invention is not restricted to any particular power source and mayinclude but is not limited to converted AC power, or external DC power.In one embodiment a battery 205 is charged by a solar charger 122.

According to an embodiment a DC-DC converter 206 is provided to convertthe 12-volt battery 205 power to the 24 volt power required to power theprogrammable logic controllers 202. However, the use of a converterdepends on the programmable logic controllers 202 utilized (theinvention is not limited to any particular converter). The MCU 118comprises, in one embodiment, a single pole momentary push button switch(PB) 208. PB 208 is used to provide a reset input into programmablelogic controllers 202. Any single pole momentary push button may be usedas is apparent to those of skill in the art, and the invention is notlimited to any particular pushbutton. MCU 118 comprises two single polesingle throw momentary push buttons PB 208, part number DS-126manufactured by Standard Manufacturing™. However, any push button switchor equivalent may be used and the invention is not limited to anyparticular type.

Of course, this section discusses exemplary portions of an exemplaryembodiment of the invention. It is understood that equivalent portionshaving equivalent devices and means may be substituted, and are readilyapparent to those of ordinary skill in the art after reading thisdisclosure.

Track Circuits

Track circuits prevent unwanted/undesirable switch operation, andre-enable switch operation. FIG. 3 is a block schematic 300 that showsone embodiment for the track circuits 102. Track circuit 102A isconnected to the main rails on both the facing point side and trailingpoint side of the points 124. Each leg, transmit and receive, ispreferably protected by lightning arrestors 308, such as part number022585-3X manufactured by Safetran Systems™. Additionally, each transmitand receive pair of wires is conditioned by a track equalizer 306 suchas part number 022700-1X manufactured by Safetran Systems™. Trackcircuit 102A operates by detecting an open circuit (or shunt) across themain rails. In the un-shunted state (or closed circuit state) trackcircuit 102A energizes relay outputs 2 and 4, thereby driving the coilof relay OS-AP 203C. Track circuit 102B is structured and operates in asimilar manner, as is readily apparent to those of skill in the art.

Of course, this section discusses an exemplary portion of an exemplaryembodiment of the invention. It is understood that an equivalent portionhaving equivalent devices and means may be substituted, and are readilyapparent to those of ordinary skill in the art after reading thisdisclosure.

Power Switch

In order to utilize the preferred switch 108, it should be modified.FIG. 4A is a diagram depicting a power-operated switch. The switch iscomprised of a hydraulic power unit 402, a hydraulic manifold 404, and aset of proximity switches 406, along with controller 110 and DTMF module112. Switch 108 operates by utilizing hydraulic force supplied byhydraulic power unit 402 to operate mechanical links to points 124. Thedirection of movement is determined by manifold 404 where the normal andreverse solenoids are controlled by controller 110. Controller 110 isconfigured to receive control inputs from pushbuttons 408 and DTMFmodule 112. Controller 110, when receiving a normal position controlinput, sets output MC17. Controller 110, when receiving a reverseposition control input, sets output MC18. Additionally, hydraulic unit402 is operated by controller 110 by setting output MC19. MC19 willremain set until position inputs MC10 or MC11 match the desired controlposition or a pressure limit is reached, set as input MC9. Inputs MC10and MC11 are set by proximity switches 406.

Upon achieving correspondence between the desired control position andthe indicated position DTMF 112 sets output 12 PTT, where PTT is used tokey radio 104A. Additionally, DTMF 112 sets output 13 AUDIO where AUDIOis used as a “line in” for radio 104A and where output 13 AUDIOcomprises pre-recorded messages. DTMF 112 is configured with one messagefor normal correspondence, one message for reverse correspondence, andone message for out of correspondence. If a control by controller 110 isreceived and switch 108 fails to achieve correspondence, as determinedby controller 110, DTMF 112 sets output 12 PTT and output 13 AUDIO wherethe message is a prerecorded message indicating an “out ofcorrespondence” condition.

Additionally, controller 110 has two inputs MC4 and MC8 that are used toprevent the setting of outputs MC17, MC18 and MC19 thereby preventingcontrol of switch 108. Inputs MC4 and MC8 are typically utilized inconjunction with track circuits to prevent the operation of switch 108when a railway vehicle is within the detection zone. Once configured,inputs MC4 and MC8 will allow operation of switch 108 when both MC4 andMC8 are set, and disallow operation of switch 108 when either input MC4or MC8 is not set.

One preferred power switch, model LP3000, has a feature forautomatically restoring switch 108 to a “normal” position following areverse movement of a railway vehicle. This option is configurable insoftware and is triggered by two inputs MC12 and MC13. Input MC12 isused to condition the controller 110 to automatically restore switch 108to the normal position following a reverse movement of a railwayvehicle. Input MC13 is used to trigger the restoration of switch 108 tothe normal position. A falling edge (removal of a signal) on input MC13will trigger the restoration of switch 108 after a configurable,pre-determined, time period. Accordingly, from the forgoing, it isapparent to one of skill in the art how to configure other powerswitches to achieve the teachings of the present discussion.

Power Switch Modifications

FIG. 4B is a diagram 400B illustrating the application and modificationsof switch 108 according to an embodiment. In order to utilize thepreferred switch 108 various modifications must be made as follows:

the B12 supply for pushbuttons 408 originates in MCU 118 and is switchedby a front contact of relay 203B,

the B12 supply for MC4 and MC13 originates in MCU 118 and is switched bya front contact of relay 203B—the signal for MC13 is accomplished by theplacement of a jumper from MC4 to MC13,

the B12 supply for manifold 404 originates in MCU 118 and is switched bya front contact of relay 203B (the normal solenoid is driven by theswitched B12 in a logical AND circuit utilizing a front contact of relay204D; the reverse solenoid is driven by the switched B12 in a logicalAND circuit utilizing a front contact of relay 204C),

the B12 supply for inputs MC10 and MC11 originates in MCU 118 and isswitched by a front contact of relay 203A (input MC10 is driven by theswitched B12 in a logical AND circuit utilizing a front contact of relay204A; input MC11 is driven by the switched B12 in a logical AND circuitutilizing a front contact of relay 204B),

input MC12 is driven by B12 that originates in MCU 118 that is switchedby a front contact of relay 204B (the switched B12 is wired throughtoggle 234 where the circuit is used to either enable or disable theauto restore feature of switch 108; proximity sensors 406 are wired toMCU 118 as inputs, where the normal proximity sensor is NWK-MACH and thereverse proximity sensor is RWK-MACH), and

output MC17 is wired to the coil of relay 204C (NWZP) in MCU 118; whereoutput MC18 is wired to the coil of relay 204D (RWZP) in MCU 118, DTMF112 input 11 is wired through controller 118 to radio 104A, DTMF 112output 12 is wired through controller 118 to radio 104A and switched bya front contact of relay 204E, and DTMF 112 output 13 is wired throughMCU 118 to radio 104A.

Software in controller 110 for switch 108 is typically pre-configured bythe manufacturer. Software utilities to modify certain operatingparameters are also typically provided by the manufacturer. In oneembodiment, controller 110 contains 65 standard configurable parametersand 4 auxiliary configurable parameters related to DTMF 112. Here, thefour auxiliary parameters are: QUERY, REVERSE, TOGGLE, and NORMAL. Thedefault setting for the auxiliary parameters is <locked>. Only theNORMAL and REVERSE parameters are modified. Each parameter is modifiedto a six digit numeric code in the form of XXXXYY, where XXXX representsa unique identification (ID) for the switch, as determined by therailroad, and YY represents the desired code to represent the givencontrol, such as 11 for NORMAL, and 22 for REVERSE. Table 1 showsuser-controlled parameters. Other parameters (except those shown inTable 1) remain at factory defaults.

Of course, the prior sections regarding the power switch discuss anexemplary portion of an exemplary embodiment of the invention. It isunderstood that equivalent portions having equivalent devices and meansmay be substituted, and are readily apparent to those of ordinary skillin the art after reading this disclosure.

Switch Circuit Controller

FIG. 5 illustrates the application of an exemplary switch circuitcontroller 114. Circuit controller 114 is mechanically linked to points124. Circuit controller 114 operates by closing certain contacts whenthe points are in various positions. Circuit controller 114 has fouroutputs, 1 through 4, wired to MCU 118 as 1NWK-SWCC, 2NWK-SWCC,1RWK-SWCC, and 2WK-SWCC respectively. Circuit controller 114 is utilizedto provide an alternate method of determining the position of the points124 from that provided by switch 108.

Contacts of circuit controller 144 operate as follows:

N—Full normal to, but not including, ¼″ from normal.

BR—¼″ from normal to full reverse.

ND—¼″ from reverse to full normal.

R—Full reverse to, but not including, ¼″ from reverse

The approach described for a MCU 118 is now continued with reference toFIG. 6. Again, this section discusses an exemplary portion of anexemplary embodiment of the invention. It is understood that equivalentportions having equivalent devices and means may be substituted, and arereadily apparent to those of ordinary skill in the art after readingthis disclosure.

Input Circuits

FIG. 6 is a diagram 600 that illustrates the inputs for logiccontrollers 202 according to an embodiment and where inputs for logiccontroller 202B are shown reflected from their actual position forclarity. Logic controllers 202 inputs operate as either a DC sourceinput, or a DC sink input, according to the wiring of the COM input.

With nomenclature:

K Indication R Reverse W Switch Z Control N Normal SWCC Switch CircuitController HB Heart Beat MACH Machine

For each logic controller 202 the COM input line is wired to N12 therebycreating a sink for all inputs. Input 0 of each logic controller 202 iswired to B12 that is switched through a front contact of relay 203C.Input 1 of logic controller 202A is wired to 1NWK-SWCC from circuitcontroller 114. Input 1 of logic controller 202B is wired to 2NWK-SWCCfrom circuit controller 114.

Input 2 of logic controller 202A is wired to 1RWK-SWCC from circuitcontroller 114. Input 2 of logic controller 202B is wired to 2RWK-SWCCfrom circuit controller 114. Input 3 of logic controllers 202 are wiredto NWK-MACH from switch 108. Input 4 of logic controllers 202 are wiredto RWK-MACH from switch 108. Input 5 of logic controllers 202 are wiredto B12 that is switched through a front contact of relay 204C. Input 6of logic controllers 202 are wired to B12 that is switched through afront contact of relay 204D. Input 7 of logic controllers 202 are wiredto B12 that is switched through a back contact of relay 204A. Input 10of logic controllers 202 are wired to B12 that is switched through aback contact of relay 204B. Input 11 of logic controllers 202 are wiredto B12 that is switched through a front contact of relay 203D. Input 12of logic controllers 202 are wired to B12 that is switched through aback contact of relay 203B. Input 13 of logic controllers 202 are wiredto B12 that is switched through pushbutton 210.

Input 14 of logic controller 202A is wired to output HB2 of logiccontroller 202B where HB2 is a pulsed output denoting the operationalheartbeat of logic controller 202B. Input 14 of logic controller 202B iswired to output HB1 of logic controller 202A where HB1 is a pulsedoutput denoting the operational heartbeat of logic controller 202A.Input 15 of logic controllers 202 are wired to B12 that is switchedthrough pushbutton 208. Of course, this section discusses exemplaryportions of an exemplary embodiment of the invention. It is understoodthat equivalent portions having equivalent devices and means may besubstituted, and are readily apparent to those of ordinary skill in theart after reading this disclosure.

Output Circuits

FIG. 7 illustrates the outputs for logic controllers 202 (outputs forlogic controller 202B are shown reflected from their actual position forclarity). Outputs for logic controllers 202 operate as DC relays wherethe outputs operate as either DC source outputs or DC sink outputsdepending on the wiring of control inputs. Each logic controller 202 hasfour control inputs labeled as COM0, COM1, COM3, and COM3, and whereCOM0 determines the operation of outputs 0, 1, 2, and 3, COM1 determinesthe operation of outputs 4, 5, 6, and 7, COM2 determines the operationof output 10, and COM3 determines the operation of output 11. Alloutputs for logic controller 202A are wired as source outputs with COM0,COM1, COM2 and COM3 wired either directly to B12, or wired to B12through logic circuits. Outputs 0 through 10 of logic controller 202Bare wired as sink outputs with COM0, COM1 and COM2 wired either directlyto N12, or wired to N12 through logic circuits. Output 11 of logiccontroller 202B is wired as a source output with COM3 wired to B12.

COM2 of logic controller 202A is wired directly to B12. COM2 of logiccontroller 202B is wired directly to N12. When output 10 of logiccontrollers 202 are set a circuit is created driving the coil of relay203A. Additionally, inputs for COM0 and COM1 of logic controllers 202are supplied by outputs 10 where output 10 of logic controller 202A isB12 and output 10 of logic controller 202B is N12. For each logiccontroller 202 COM0 and COM1 are switched through front contacts ofrelay 203A. A failure of either logic controller to set output 10 willopen the circuit for relay 203A thereby opening all circuits for outputs1 through 7 of logic controllers 202.

Output 0 of logic controllers 202 are not used. Output 1 of logiccontrollers 202 creates a circuit for the RED aspect of positionindicators 116. Outputs 1 of logic controllers 202 are switched throughfront contacts of relay 203A. Additionally, B12 and N12 is suppliedthrough back contacts of relay 203A creating a circuit for the REDaspect of position indicators 116 when relay 203A is in the openposition. Output 2 of logic controllers 202 create a circuit for theYELLOW aspect of position indicators 116. Output 3 of logic controllers202 create a circuit for the GREEN aspect of position indicators 116.Output 4 of logic controllers 202 create a circuit to drive the coil ofrelay 204A. Output 5 of logic controllers 202 create a circuit to drivethe coil of relay 204B. Output 6 of logic controllers 202 create acircuit to drive the coil of relay 203B. Output 7 of logic controllers202 create a circuit to drive the coil of relay 204E. Output 10 of logiccontrollers 202 create a circuit to drive the coil of relay 203A. Output11 of logic controllers 202 operate as a pulsed output denoting theoperational heartbeat of the logic controllers 202. Output 11 of logiccontroller 202A is denoted as HB1 and is wired to input 14 of logiccontroller 202B. Output 11 of logic controller 202B is denoted as HB2and is wired to input 14 of logic controller 202A. Like other sections,this section discusses exemplary portions of an exemplary embodiment ofthe invention. It is understood that equivalent portions havingequivalent devices and means may be substituted, and are readilyapparent to those of ordinary skill in the art after reading thisdisclosure.

PLC Program

One exemplary program for operating a method according to the inventionoperates in two distinct modes: initialization and operation. Theinitialization mode is entered when the logic controllers 202 arepowered up or a reset signal is received on input 15. During theinitialization mode various timers and flags are set to allow theprogram to achieve a stable operating state. Additionally the programbegins generating a periodic heartbeat on output 11. The heartbeat isprogrammed for a continuous duty cycle of 3 seconds on and 7 secondsoff. Each logic controller 202 reads the other logic controllers 202heart beat on input 14. If during the initialization, or operationalmodes the received heartbeat is not detected or falls outside of theallowable timing parameters output 10 is turned off thereby openingcircuits on outputs 0 through 7. In this state the indicators 116 willdisplay a RED aspect, and switch 108 will be prevented from beingcontrolled by the open circuit on relay 203B. Additionally, during theoperating mode program will turn off output 10 under several conditionswhere an input does not agree with a calculated state or an output.These checks include certain feedback circuits that include inputs 7,10, and 12.

Once the program initializes it enters the operational mode. During thismode the program executes in a continuous loop that reads the inputs andsets the outputs according to the programmed logic. In addition to theoperations already described, the general operation of a system for aremotely controlled switch according to various embodiments iscontinued. This section discusses an exemplary method of an exemplaryembodiment of the invention. It is understood that equivalent methods(and portions of methods) having equivalent or substantially similarends may be substituted, and are readily apparent to those of ordinaryskill in the art after reading this disclosure. To further aidunderstanding of the invention, program mnemonics are provided with thedrawings as the Mnemonics Listing.

Operation

One method according to the invention is shown in FIG. 8 as a switchalgorithm 800, which may be practiced as software. The switch algorithm800 operates by applying both software logic and relay logic to theoperation of switch 108. Four goals of the switch algorithm 800 are: toallow the remote control of switch 108, provide feedback on the statusof switch 108 to railway personnel, prevent the control of switch 108when occupied or other operating conditions require, and prevent thecontrol of switch 108 in the presence of a component or logical failure.

Operational control of the switch algorithm 800 begins with a receivewireless command act 810 in which the receipt of a radio dual tonemulti-frequency command received by DTMF 112 that is generated by radio104B. DTMF 112 decodes the message, and once validated to match theprogrammed codes in a validate codes act 820, the DTMF 112 causescontroller 110 to execute the control by setting outputs MC17 for aNORMAL command, or MC18 for a REVERSE command in a control command act830. These outputs set relays 204C and 204D, respectively. These relaysdrive the solenoids of manifold 404 but are switched by relay 203B.Relay 203B is the Lock Relay, set (on) when unlocked and reset (off)when locked. Relay 203B is set only when track circuits 102 areun-occupied, certain software timers are not running, and relay 203A isset (on). If relay 203B is reset, switch 108 is locked and cannot becontrolled. Accordingly, in a check relay act 840, relay 203B is queriedto determine if it is in a condition for operation. If the switch 203Bis in a condition for operation, then the switch algorithm 800 proceedsto a detect correspondence query 850. If the switch 203B is not in acondition for operation, then the relay 203B is in a reset mode and theswitch 108 is locked as shown in the relay off act 845.

The software timers that govern the operation of relay 203B may includea 15-minute approach timer. The approach timer is used to lock theswitch for 15 minutes after the switch has reached correspondence asindicated by logic controller 202 inputs 1, 2, 3, 4, 5, 6, 7, and 8. Asindicated above, while the approach timer is running switch 108 cannotbe re-controlled. The approach timer can be slotted off by the occupancytrack circuits 102.

When controller 110 detects correspondence as governed by inputs MC10and MC11 in the detect correspondence query 850, controller 110 causesDTMF 112 to transmit via radio 104A a pre-recorded message—one fornormal correspondence and one for reverse correspondence in a transmitact 860. Thus, if controller 110 detects a failure to achievecorrespondence within a predetermined time after receiving a controlcontroller 110 causes DTMF 112 to transmit an out of correspondencemessage on radio 104A in an correspondence failure act 855.

Feedback to railway personnel on the condition of points 124 in providedin a condition indicator act 870, and includes the pre-recorded messagestransmitted following a control message and also the display of theaspects for indicators 116. Indicators 116 are normally turned off andare only turned on following the receipt of a control message or ifrelay 203A is reset (off). The GREEN aspect of indicator 116 is used toindicate the points 124 are in the normal position. The YELLOW aspect ofindicator 116 is used to indicate the points 124 are in the reverseposition. The RED aspect of indicator 116 is used to indicate points 124are in an unknown, indeterminate, or illegal, position or the system hassuffered a failure. Exemplary failures in the system may include afailure to detect a heartbeat as previously described and failuresrelating to the states and status of various inputs and outputs.

Thus, the switch algorithm 800 logically validates that all positionindications on inputs 1, 2, 3 and 4 are in agreement according to thelogically calculated state. Additionally the switch algorithm 800validates that the state of relay 203B matches the calculated state ofoutput 6. Any failure of the system in either the heartbeat or thecalculated states causes the output 10 of logic controllers 220 to beturned off. This opens relay 203A and puts the system in the statepreviously described. Once in this state the system is manually reset inorder to allow remote control of switch 108. Similarly, the system isreset by the application of push button 208A.

Of course, it should be understood that the order of the acts of thealgorithms discussed herein may be accomplished in different orderdepending on the preferences of those skilled in the art, and such actsmay be accomplished as software, and that equivalent methods (andportions of methods) having equivalent or substantially similar ends maybe substituted, and are readily apparent to those of ordinary skill inthe art after reading this disclosure. Furthermore, though the inventionhas been described with respect to a specific preferred embodiment, manyadvantages, variations and modifications will become apparent to thoseskilled in the art upon reading the present application. It is thereforethe intention that the appended claims and their equivalents beinterpreted as broadly as possible in view of the prior art to includeall such variations and modifications.

TABLE 1 PARAMETER SET TO DESCRIPTION EXPLANATION 06 00 Self Restore Setsself restore function to be controlled by MC12 07 05 Restore Time (sec)Seconds after falling edge of MC13 to control switch normal for selfrestore. 08 00 Restore Time (min) Minutes after falling edge of MC13 tocontrol switch normal for self restore 30 00 Toggle function Disablestoggle input MC2 31 01 Normal/Reverse Function Enables inputs MC1 andMC3 44 01 Throw Disable MC8 Set input MC8 to act as a normally opencontact. 45 00 Throw Disable MC4 Set input MC4 to act a a normallyclosed contact. 47 01 Third Voice Enable Sets DTMF 112 to transmit outof correspondence message when necessary. 63 90 Third Voice IntervalSets DTMF 112 to transmit out of correspondence message every 90 minuteswhen switch 108 is out of correspondence.

Mnemonics 1/8 00000 LOD M0014 00001 OUT Q0000 00002 LODN Q0002 00003ANDN Q0003 00004 AND M0004 00005 AND Q0010 00006 OUT Q0001 00007 LODM0005 00008 OUT Q0002 00009 LOD M0003 00010 OUT Q0003 00011 LOD M000700012 ANDN M0017 00013 ANDN I0006 00014 AND Q0010 00015 ANDN M0035 00016ANDN M0027 00017 OUT Q0004 00018 LOD M0006 00019 ANDN I0005 00020 ANDQ0010 00021 ANDN M0035 00022 ANDN M0027 00023 OUT Q0005 00024 LOD M000100025 AND M0002 00026 AND Q0010 00027 SET Q0006 00028 TIM T017 010000030 LODN M0001 00031 LODN M0002 00032 TIM T021 0020 00034 ORLOD 00035ORN Q0010 00036 RST Q0006 00037 LOD M0001 00038 OUT Q0007 00039 LODNM0010 00040 ANDN M0000 00041 OUT Q0010 00042 LODN M0010 00043 AND M005000044 OUT Q0011 00045 LOD M0301 00046 SET M0000 00047 SET M0027 00048LOD M0000 00049 TIM T001 0100 00051 RST M0000 00052 LOD M0002 00053 RSTM0027 00054 LOD I0000 00055 AND I0011 00056 TIM T002 0100 00058 OUTM0001 00059 LODN M0012 00060 ANDN M0013 00061 AND M0002 00062 LOD M002000063 ANDN M0027 00064 ORLOD 00065 OR M0017 00066 LOD I0013 00067 ANDNM0032 00068 AND M0001 00069 ORLOD 00070 OUT M0002 00071 LOD I0013 00072TIM T010 0020 00074 OUT M0032 00075 LODN M0002 00076 AND Q0010 00077ANDN M0011 00078 TIM T004 9000 00080 SET M0017 00081 LOD M0017 00082 LODI0005 00083 OR I0006 00084 ANDLOD 00085 RST M0017 00086 LOD M0011 00087ANDN M0002 00088 ANDN M0027 00089 SET M0020 00090 LOD M0002 00091 ANDQ0006 00092 TIM T023 0010 00094 RST M0020 00095 LODN M0010 00096 ANDNM0030 00097 AND M0012 00098 ANDN Q0006 00099 ANDN I0013 00100 OUT M000300101 LODN M0010 00102 ANDN M0030 00103 AND M0013 00104 ANDN Q0006 00105ANDN I0013 00106 OUT M0005 00107 LODN M0002 00108 LODN M0001 00109 SOTU00110 ORLOD 00111 LOD M0015 00112 ANDN M0026 00113 ORLOD 00114 OR I001300115 SET M0004 00116 LOD M0004 00117 LOD M0016 00118 OR M0023 00119ANDLOD 00120 AND M0001 00121 TIM T003 3000 00123 LOD M0002 00124 SOTD00125 ORLOD 00126 RST M0004 00127 RST M0023 00128 RST M0016 00129 LODM0011 00130 LODN M0001 00131 AND M0002 00132 ORLOD 00133 LOD I0013 00134SOTU 00135 ORLOD 00136 SET M0023 00137 LOD M0004 00138 ANDN M0023 00139TIM T005 9000 00141 SET M0016 00142 LODN M0014 00143 AND I0001 00144 ANDI0003 00145 ANDN I0002 00146 ANDN I0004 00147 OUT M0007 00148 LODN M001400149 AND I0002 00150 AND I0004 00151 ANDN I0001 00152 ANDN I0003 00153OUT M0006 00154 LODN I0012 00155 OR I0005 00156 OR I0006 00157 ANDNQ0006 00158 LOD Q0006 00159 AND I0012 00160 ORLOD 00161 LODN Q0004 00162ANDN I0007 00163 ORLOD 00164 LODN Q0005 00165 ANDN I0010 00166 ORLOD00167 LOD 00004 00168 AND I0007 00169 ORLOD 00170 LOD Q0005 00171 ANDI0010 00172 ORLOD 00173 TIM T000 0050 00175 OR M0042 00176 OUT M001000177 LODN I0000 00178 ORN I0011 00179 BPS 00180 TIM T006 0050 00182 OUTM0011 00183 BPP 00184 TIM T019 0300 00186 OUT M0030 00187 LOD M000700188 AND M0022 00189 OUT M0012 00190 LOD M0006 00191 AND M0021 00192OUT M0013 00193 LOD I0001 00194 OR I0003 00195 LOD I0002 00196 OR I000400197 ANDLOD 00198 TIM T007 0010 00200 SET M0014 00201 LOD I0015 00202SOTU 00203 RST M0014 00204 LOD M0007 00205 SOTU 00206 LOD M0006 00207SOTU 00208 ORLOD 00209 LOD I0005 00210 SOTU 00211 ORLOD 00212 LOD I000600213 SOTU 00214 ORLOD 00215 SET M0015 00216 LOD M0015 00217 TIM T0080030 00219 RST M0015 00220 LOD I0005 00221 SOTU 00222 AND Q0006 00223ANDN M0026 00224 SET M0022 00225 LOD M0003 00226 SOTD 00227 AND M001200228 LOD I0006 00229 AND Q0006 00230 ORLOD 00231 LOD M0035 00232 SOTU00233 ORLOD 00234 LOD M0017 00235 SOTU 00236 ORLOD 00237 OR I0013 00238RST M0022 00239 LOD I0006 00240 SOTU 00241 AND Q0006 00242 SET M002100243 LOD M0005 00244 SOTD 00245 AND M0013 00246 LOD I0005 00247 ANDQ0006 00248 ORLOD 00249 LOD M0035 00250 SOTU 00251 ORLOD 00252 LOD M001700253 SOTU 00254 ORLOD 00255 OR I0013 00256 RST M0021 00257 LOD Q000600258 CMP >= (W) T017 — 30 — M0024 — 00262 CMP <= (W) T017 — 80 — M0025— 00266 LOD M0024 00267 AND M0025 00268 SET M0026 00269 LOD M0026 00270TIM T018 0055 00272 RST M0026 00273 LODN M0007 00274 ANDN M0006 00275LODN I0005 00276 ORN I0006 00277 ANDLOD 00278 TIM T026 0020 00280 ORM0301 00281 SET M0035 00282 LOD I0005 00283 OR I0006 00284 RST M003500285 LOD I0014 00286 SOTU 00287 OUT M0041 00288 LOD I0014 00289 SOTD00290 OUT M0040 00291 LOD M0041 00292 ANDN T012 00293 LOD M0040 00294ANDN T011 00295 ORLOD 00296 LOD I0014 00297 AND T013 00298 ORLOD 00299LODN I0014 00300 AND T014 00301 ORLOD 00302 ANDN M0301 00303 ANDN M000000304 SET M0042 00305 LOD I0015 00306 LOD I0012 00307 ANDN I0005 00308ANDN I0006 00309 AND I0007 00310 AND I0010 00311 ORLOD 00312 RST M004200313 LOD I0014 00314 ANDN I0015 00315 BPS 00316 TIM T011 0020 00318 BPP00319 TIM T013 0040 00321 LODN I0014 00322 ANDN I0015 00323 BPS 00324TIM T012 0060 00326 BPP 00327 TIM T014 0080 00329 LODN M0043 00330 ANDNM0042 00331 ANDN I0015 00332 OUT M0050 00333 TIM T015 0030 00335 LODT015 00336 LOD M0043 00337 ANDN T016 00338 ORLOD 00339 OUT M0043 00340TIM T016 0070 00342 END

1. A railroad switch system, comprising: a railroad track in a darkterritory, the railroad track comprising a main track segment, a firsttrack segment, a second track segment, and a switch point thatselectively couples the main railroad track segment to the first tracksegment or the second track segment; a power switch coupled to theswitch point; a switch controller for controlling the operation of thepower switch; a dual tone multiple frequency (DTMF) module for receivinga signal, the DTMF coupled to the switch controller; the switchcontroller coupled to a main control unit (MCU), the MCU adapted toreceive a wireless signal via a wireless communications device; a switchcircuit controller coupled between the MCU and the switch point; a firsttrack circuit coupled between the first track segment, main tracksegment and the MCU; and a second track circuit coupled between thesecond track segment and the MCU.
 2. The system of claim 1 furthercomprising a second wireless communications device that iscommunicatively coupled to the first wireless communications device. 3.The system of claim 1 wherein the system is powered with a remote powersource coupled to the switch.
 4. In a dark territory portion of arailroad track, a switch system comprising: a controller coupled to arailroad main control unit (MCU); a dual tone multiple frequency module(DTMF) coupled to the controller, the DTMF coupled to the MCU; theconnector adapted to couple to a switch point, the switch point locatedin a dark territory of a railroad track; and the MCU coupled to awireless receiver.